1. Field
Example embodiments relate to optical input/output (I/O) devices including a waveguide, a coupler, and a photodetector, and methods of manufacturing the same.
2. Description of Related Art
An optical input/output (I/O) device is a device configured to transmit and receive data using light. The optical I/O device may include a coupler optically connected to optical fibers, a photodetector configured to convert an optical signal and an electric signal into each other, and a waveguide configured to optically connect the coupler and the photodetector.
A conventional method of manufacturing an optical input/output (I/O) device includes forming a trench in a substrate, which is generally a bulk silicon wafer, forming a waveguide in the trench, and forming a photodetector on a top surface of the waveguide. That is, in the conventional optical I/O device, the photodetector protrudes from a top surface of the wafer.
Thus, when memory cells (e.g., dynamic random access memory (DRAM) cells) are formed on the substrate, the photodetector may be damaged due to a process of forming the memory cells.